Question: Multiply.
Solution: When a number is next to a variable, it means they are multiplied. So, $({-3}{m^5})({-2}{m^4})$ is the same as $({-3})({m^5})({-2})({m^4})$. Now we can rearrange the factors because multiplication is commutative (a fancy way of saying that the order in which we multiply things doesn't matter). ${(-3)(-2)}{(m^5)(m^4)}$ Then simplify, and we're done! ${6}{m^{9}}$